Should I use a single plate or a mesh of plates for modeling slabs in STAAD.Pro

Applies To
Environment: ALL
Area: Analysis
Subarea: Modeling
Original Author:Sye Chakraborty, Bentley Technical Support Group


I am modeling a slab in STAAD.Pro. Should I use a single plate or should I generate a mesh of plates ?


Related question :


Should I use Add Plate option or Generate Surface Mesh option to model the slab ?


A slab has to be modeled using a mesh of plates. You should not model it using a single plate element because if you do so, the slab will only connect to the rest of the structure at the corners. So if you have beams along the edges and columns at the four corners of the slab, the slab would only connect to the columns but not to the beams. Hence the load from the slab will be transferred to the columns directly without bothering the beams and so the load path would not be accurate. Hence you should always use a mesh of plates and the beams at the edges should also be divided in line with the plate mesh so that connectivity is established at the common nodes along the edge.


Now that we have established that we have to use a plate mesh as opposed to a single plate to model the slab, let us examine which of the two options we should use. The Add Plate adds one single plate at a time. So if you have to generate the plate mesh using this option, you would have to repeat the process multiple times. You would have to create the nodes first and then create the plates one at a time using this option which is time consuming. The Generate Surface Mesh option on the other hand automates the generation of the plate mesh and allows one to generate the entire plate mesh in one shot. So the answer is, using the Generate Surface Mesh is more suited to modeling a slab.